Environmental Effect on Strength and Fracture of Advanced CFRP Composite
Yoshiyuki TOMITA, Kojiro MORIOKA, Takashi ISEKI and Seiji NAKAHORI
Abstract:A long carbon fiber with 5.5 Gpa in average tensile stress-reinforced epoxy plastic (CFRP) has been studied to determine the environmental effect on the tensile stress and fracture behavior of the advanced CFRP. The cross-ply laminates (0/90 plies) were used in this study. Unnotched and notched tensile tests were conducted using Instron machine from ambient temperature to 130. The tensile specimens were immersed in distilled water, 40 wt.% nitric acid and 40 wt.% sulfuric acid at ambient temperature for a month (designated as distilled-water, nitric-acid and sulfuric-acid specimens, respectively). The results were compared with those obtained by the non-immersed specimens. The tensile fracture stresses of unnotched and notched specimens increased in the following ascending order: non-immersion, distilled-water, nitric acid and sulfuric acid. However, there was little difference in the tensile stress between immersed and non-immersed specimens at 130 for unnotched specimens and at and above 80 for the notched specimens. The results are described and discussed in terms of fractography, EPMA and FT-IR analysis and so on. Key Words:CFRP composite, Cross-ply laminates (0/90 plies), Environmental effect, Strength and fracture mechanism, Fractography, FT-IR analysis